Work proposed for the following year includes: (A) Continue perturbation and tracer experiments documenting metabolite compartmentation in Dictyostelium; (B) Finalize enzyme characterizations and inhibition studies (esp. by NH3 and NADH) of TCA enzymes essential to a transition model of the TCA cycle. (C) Construct a transition model of TCA cycle and a steady state model of the two cell types to interpret the tracer experiments in (A) above.